Chap. 47.] SPONGES. 519 



vapour of it in boiling water being inhaled by the patient. 

 Mixed with alum, it removes porrigo ; and, used daily with 

 water, as a fomentation, it removes offensive odours of the 

 armpits. Used in combination with wax, it heals ulcers pro- 

 duced by pituitous secretions, and, similarly employed, it is 

 very useful for affections of the sinews. For the cure of the 

 cceliac flux, it is used in the form of an injection. Many 

 authorities recommend the use of it, with oil, as a friction 

 when cold shiverings are just coming on; as also, for the re- 

 moval of leprous spots and freckles. It is a good plan also, 

 to use a sitting-bath made with an infusion of nitrum, for the 

 cure of gout, atrophy, opisthotony, and tetanus. 



Both salt and nitre, boiled with sulphur," become petrified. 



CHAP. 47. (11,) SPONGES, AND THE EEMEDIES DEKIVBD FROM 



THEM I NINETY-TWO OBSERVATIONS THEEEON. 



We have already, 1 when speaking of the marine productions, 

 described the various kinds of sponge. Some authorities make 

 the following distinctions : they regard as males 2 those sponges 

 which are pierced with more diminutive holes, are more com- 

 pact in form and more ready to imbibe, and are stained, to 

 satisfy luxurious tastes, in various colours, sometimes purple 

 even : those, on the other hand, which have holes, larger and 

 running into one another, they consider to be females. Among 

 the male sponges, too, there is one kind, harder than the others, 

 the name given to which is " tragi," 3 and the holes of which 

 are extremely small and numerous. Sponges are made white 

 artificially ; the softest being chosen for the purpose, and after 

 they have been steeped the whole summer through with the 

 foam of the sea. They are then exposed to the action of the 

 moon and hoar-frosts, being turned upside down, or, in other 

 words, with that part upwards by which they formerly ad- 

 hered to the rocks, the object being that they may become 

 white throughout. 



That sponges are animated beings, we have already stated ; 



9& Beckmann considers that this statement throws some light on the 

 ohscure passage, commented on in Note 77, p. 514. See Hist. Inv. Vol. 

 II. p. 503. John's Ed. l In B. ix. c. 69. 



3 No such distinction, of course, really exists ; sponge being in reality 

 a fibrous tissue formed by minute animals. 



3 " Goats," literally. 



